It is one of the more curious distortions of the recent past that, 30 years ago, World War I seemed farther away from us than it does today. The uniforms—the soup-bowl helmets, the puttees, the choke-collared tunics—were as quaint as those lozenge-shaped tanks that tilted their way back and forth across the skinned gray landscape. And, in the darkening political climate of the 1960s, the conflict increasingly came to be what it had been to the generation or the 1930s: war as abject idiocy, four years of men moving toward their death, in the combat artist Kerr Eby’s phrase, “like maggots in a cheese.”

World War II, on the other hand, had been brisk, modern, a war of quick, decisive movement brought to a triumphant conclusion by men and women then still in their early forties. And most of all, it was a righteous war; its predecessor had been the bloody-minded fumbling of imperialists and kings.

But time has shifted the parallax, as time always does, and today, the dismal terrain of the Western Front no longer seems quite so remote to us. As John Lukacs suggests in his essay marking the 75th anniversary of its ending, the war that began in 1914 turned the currents of history. He sees our century as having lasted just 75 years, from the fall of Belgium to the fall of Russian communism; and America’s entry into the fight was of greater moment to this century than the rise and tenure of the first Marxist state, to which the war gave birth.

And it’s possible that the old certainties about the war’s moral futility are eroding. There are still those who claim (to pick one extreme example) that Britain caused it all by refusing to let Germany build a stronger fleet; but then there are others who are asking questions like the one posed by the Australian historian Trevor Wilson at the end of his huge, panoramic, altogether admirable book about Britain’s role in the conflict, The Myriad Faces of War. He quotes the famous “backs to the wall” order that Sir Douglas Haig issued in the spring of 1918 as his troops faltered under the final German onslaught: “The safety of our homes and the freedom of mankind alike depend on the conduct of each one of us at this critical moment.” This might “be dismissed as the empty rhetoric of an impoverished command,” says Wilson, but then he goes on to quote a very different voice, that of Haig’s contemporary H.W. Massingham, in The Nation: “In the full brunt of the German assault on France, the true character of the war stands revealed. Vain projects of Imperialism obscured it, and vainer diversions of strategy. Both have disappeared. … The war emerges from these mists, not as a war of adventure but morally and physically as a war of defence. … The war was not for colonies, Imperial ambitions, or a balance of power. It was